Add everything that's needed to have a standalone setup of the XSGMII
mode without having to rely on previous U-boot setup. This includes
patch sequences for the SerDes and extensions of symbol error reset and
reading.
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/21762
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>